Effects of supplementation of betaine hydrochloride on physiological performances of broilers exposed to thermal stress
Authors Singh A, Ghosh T, Creswell D, Haldar S
Received 20 April 2015
Accepted for publication 14 May 2015
Published 6 July 2015 Volume 2015:7 Pages 111—120
Checked for plagiarism Yes
Review by Single-blind
Peer reviewer comments 3
Editor who approved publication: Dr Peter Koulen
Abhay K Singh,1 Tapan K Ghosh,1 David C Creswell,2 Sudipto Haldar1
1Department of Animal Nutrition, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, India; 2Creswell Nutrition, Sydney, Australia
Background: Betaine has the potential to spare methionine and choline as methyl-group donors, and is thought to improve broiler performance under conditions of stress. An experiment was conducted to ascertain the effects of supplemental betaine on performances and physiological responses of broilers exposed continuously to thermal stress.
Materials and methods: Male broilers (n=128, divided into four groups, with eight replicate cages in a group) received diets containing suboptimal levels of methionine and metabolizable energy and supplemented with 1.3 g/kg and 2 g/kg betaine hydrochloride from day 1 to 38. The positive control (PC) did not contain supplemental betaine, and the negative control (NC), to which betaine was added, was deficient in methionine and energy and devoid of added choline. The experiment included assessment of growth, feed-conversion ratio, rectal temperature and respiration rates, and assay of blood hormones and metabolites.
Results: Betaine at both the levels of inclusion improved live weight and feed intake over the PC and the NC groups. Rectal temperature and respiration rates were also lower in the betaine-supplemented groups, indicating a sequestering effect of betaine on metabolic rates of thermally stressed broilers. Carcass yield was unaffected. Betaine-supplemented groups had better thyroid activity than the NC and PC groups of birds.
Conclusion: Based on this study, it was inferred that in tropical countries betaine may be effectively used to ameliorate the negative impact of high ambient temperature in broiler chickens. The findings also suggest that at an appropriate dose, betaine may spare some quantity of dl-methionine and dietary energy to support the growth process of heat-stressed broilers. However, further studies are warranted to assign a definite methionine and energy matrix to supplemental betaine that can be used in broiler diets without inviting any risk of drop in production.
Keywords: betaine, broiler chickens, heat stress, performance, physiological responses
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]